Recent developments in the automotive industry have resulted in higher engine output in a more compact engine compartment. As a result, power transmission belts on these engines have been required to operate under higher load and at high tensions. Under such high load conditions on certain drives, belts can turn over in their pulleys, which is very undesirable and lead to premature failure. To meet such demands, it is desirable to increase the dynamic stiffness of the belts. Unfortunately, increasing the dynamic stiffness of the compound used in the belt tends to increase the tan delta values of the rubber compound. Therefore, there exists a need for a new and improved belt to meet the demand in the industry which exhibits good dynamic stiffness and good tan delta values.
The present invention relates to a single V-grooved power transmission belt that is characterized by a rubber composition containing a mixture of natural rubber and a polybutadiene adduct of maleic anhydride.